experimental attachment support using webtorrent.

persist attached file (local added torrents) using indexedDB/localForage lib.

home.html

@@ -126,6 +126,9 @@
           <form class="post-area-new">
             <textarea placeholder="New Post..."></textarea>
             <div class="post-area-extras">
+              <div class="post-area-attach" style="display: none;">
+                <input type="file" id="fileInputAttach" style="font-size: 10px;/>
+              </div>
               <span class="post-area-remaining">140</span>
               <button class="undo-unicode disabled" disabled="disabled">undo</button>
               <button class="post-submit disabled" disabled="disabled">post</button>

js/interface_common.js

@@ -930,8 +930,10 @@ function applyShortenedURI(short, uriAndMimetype) {
             if ($.Options.WebTorrent.val === 'enable') {
                 if ($.Options.WebTorrentAutoDownload.val === 'enable' &&
                     followingUsers.indexOf(fromUser) !==-1) {
-                    twister.torrentIds[long] = true;
-                    $.localStorage.set('torrentIds', twister.torrentIds);
+                    if(!(long in twister.torrentIds)) {
+                        twister.torrentIds[long] = true;
+                        $.localStorage.set('torrentIds', twister.torrentIds);
+                    }
                     startTorrentDownloadAndPreview(long, previewContainer, isMedia);
                 } else {
                     // webtorrent enabled but no auto-download. provide a link to start manually.
@@ -987,9 +989,11 @@ function webtorrentFilePreview(file, previewContainer, isMedia) {
         var imagePreview = $('<div class="image-preview" />');
         previewContainer.append(imagePreview);
         file.appendTo(imagePreview[0], function (err, elem) {
-            elem.pause();
+            if ('pause' in elem) {
+                elem.pause();
+            }
         });
-        imagePreview.find("video").removeAttr("autoplay").get(0).pause();
+        imagePreview.find("video").removeAttr("autoplay");
     } else {
         file.getBlobURL(function (err, url) {
             if (err) return console.error(err)

js/interface_home.js

@@ -310,7 +310,7 @@ function initWebTorrent() {
     localStorage.removeItem('debug')
 
     WEBTORRENT_ANNOUNCE = $.Options.WebTorrentTrackers.val.split(/[ ,]+/)
-    $.getScript('js/webtorrent.min.js', function( data, textStatus, jqxhr ) {
+    $.getScript('js/webtorrent.min.js', function() {
         WebTorrentClient = new WebTorrent();
         console.log("WebTorrent started")
         WebTorrentClient.on('error', function (err) {
@@ -322,14 +322,78 @@ function initWebTorrent() {
 
         if ($.localStorage.isSet('torrentIds'))
             twister.torrentIds = $.localStorage.get('torrentIds');
-        if ($.Options.WebTorrentAutoDownload.val === 'enable') {
-            for (var torrentId in twister.torrentIds) {
-                if( twister.torrentIds[torrentId] === true ) {
-                    console.log("WebTorrent auto-download: " + torrentId);
-                    WebTorrentClient.add(torrentId);
+
+        $.getScript('js/localforage.min.js', function() {
+            localforage.setDriver([localforage.INDEXEDDB,localforage.WEBSQL]).then(function() {
+                for (var torrentId in twister.torrentIds) {
+                    if( twister.torrentIds[torrentId] ) {
+                        if (typeof(twister.torrentIds[torrentId]) === "string") {
+                            // get blob file to restart seeding this file
+                            var onGetItem = function(torrentId, err, data) {
+                                console.log("onget:", torrentId, err, data)
+                                if (err || data === null) {
+                                    // error reading blob, just add torrentId
+                                    console.log("WebTorrent auto-download: " + torrentId + 
+                                                " (previously seeded as: " + twister.torrentIds[torrentId] + ")" );
+                                    WebTorrentClient.add(torrentId);
+                                } else {
+                                    var fileBlob = new File([data], twister.torrentIds[torrentId]);
+                                    console.log('WebTorrent seeding: "' + twister.torrentIds[torrentId] +
+                                                '" size: ' + data.size);
+                                    WebTorrentClient.seed(fileBlob);
+                                }
+                            }
+                            localforage.getItem(torrentId, onGetItem.bind(null, torrentId));
+                        } else if ($.Options.WebTorrentAutoDownload.val === 'enable') {
+                            console.log("WebTorrent auto-download: " + torrentId);
+                            WebTorrentClient.add(torrentId);
+                        }
+                    }
                 }
-            }
-        }
+
+                // setup attach button
+                $(".post-area-attach").show();
+                var fileInput = $("#fileInputAttach");
+                fileInput.on('change', function(event) {
+                    var file = fileInput[0].files[0];
+                    var seedingTorrent = undefined;
+                    for (var i = 0; i < WebTorrentClient.torrents.length; i++) {
+                        var torrent = WebTorrentClient.torrents[i];
+                        if (torrent.length === file.size &&
+                            torrent.files[0].name === file.name) {
+                            seedingTorrent = torrent;
+                        }
+                    }
+                    var saveBlobFile = function(infoHash,file) {
+                        var magnetLink = "magnet:?xt=urn:btih:" + infoHash
+                        var blobFile = new Blob([file]);
+                        localforage.setItem(magnetLink, blobFile);
+                        twister.torrentIds[magnetLink] = file.name;
+                        $.localStorage.set('torrentIds', twister.torrentIds);
+                        return magnetLink;
+                    }
+                    if (seedingTorrent) {
+                        var magnetLink = saveBlobFile(seedingTorrent.infoHash,file);
+                        console.log('Already seeding ' + magnetLink);
+                        shortenMagnetLink(event,magnetLink);
+                    } else {
+                        WebTorrentClient.seed(file, function (torrent) {
+                            var magnetLink = saveBlobFile(torrent.infoHash,file);
+                            console.log('Client is seeding ' + magnetLink);
+                            shortenMagnetLink(event,magnetLink);
+                        });
+                    }
+                });
+            });
+        });
+    });
+}
+
+function shortenMagnetLink(event,magnetLink) {
+    var uri = prompt(polyglot.t('shorten_URI_enter_link'), magnetLink);
+    var textArea = $(event.target).closest('form').find('textarea');
+    newShortURI(uri, function(long,short) {
+        textArea.append(short);
     });
 }